SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '41515232eee5c2ac73829a7af8f1eac2b4bda3ef7e34db564a84938314fc06dd' 
  AND token = 'zOa0WpliTzWaI5LHuvXXbCHvpCg23SGmdMRF4nG2AWE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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