SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5cda77d4bb427afb6d5ea6785887199782ce75d47bacc5664a2a176f4bcc45a6' 
  AND token = 'uVnK+8g72QN7uwutOgT3e1dKHR+/ljZBPErm1i+UZJo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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