SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7bc406fd1a1d71a33f647ae6b24c725d549c15d4150d179af6b82798d6b40c27' 
  AND token = 'FbPJDTljh1qL6Qjr4oB8gRPQ17QgkPZbBYMdRUF+/l4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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