SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2a5d3251200213c39127fd5196183604f80e9a8276c2d7cae9ddaf4360ecf9c8' 
  AND token = 'Gmc64h3Gr/8mzOVIhMdkFoemFzawnekuPlZuH7gEOGk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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