SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7e3c8756b14787582affacb9f27eec54ac867bd7431f7d9c2b8c566648b47968' 
  AND token = 'kqKQZd7Y42ef19Nvuiz+F9pRPcJgC1tsA5urj6sMKEk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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