SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e5ee2f873bf55d43d067fcc84352b794861534f47cddbc7b126e7f9920417c9e' 
  AND token = 'kePYt1lFuzVdoHCE4a+iai+35gmit/u4qFRDD2Fjz/0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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