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SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd3bef6f4a14aa4bbc6b1b85240e2a6ed4a8f66d0fa5d7a199999e417de0a5143' 
  AND token = 'ayZSeNigtlSLXKtEqiitPK9jmy48/w+hG1UtFdy6uGg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}