SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'df3fdce420e91e46766925d42683ef75ebc6c043bb481eacb7e9db73871cd8cf' 
  AND token = 'oTT/u0v+TeIjff6QosL96VC4yQqUbKnbLByeEmSSgbM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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