SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'be20a665a1acbe76e63aca949198ba78870c8b732b9abd87bac016eea9431cab' 
  AND token = 'WbPZ0GH8kt69TJJuH/nErFT9WwJisFYPj9jSnSobySU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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