SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '436aa33b57549c6c730dc4f1774a08f0ce4fde8825a52083b364492e4876930e' 
  AND token = 'qDHwlpDpqN88Mt68JxqnkSIs7OSU9ZcbSeCWzEfINsk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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