SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f38fb19c1e67009e682be32dbb208f47c0eb518fd34cdb266f29d78eb9636f9d' 
  AND token = 'psM4jdpNRPsRZIBKTDtue0w3Z8CMq3tRQSFQC7yjc9M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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