SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e47943403649d20a050979f4149b6bccf7a83a6917cd93a088ba32c5d3cc3676' 
  AND token = 'bblsLKc2yOmFd7Nu7qOnwFMxS4cM/OSOmlZB4Et6dP4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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