SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5d93b489956c3e21c64e850c719bc0bd9e01f8105b9343f27972619d66b5727f' 
  AND token = 'GgKBvlp9M3NBJjjzJE/gxnpaxZfHBzYgEWsmBiKNfHg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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