SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7e0639f4addb7986bbab7c9a1e65d5e867dea7dd1635ea852afcc3eebf3ed747' 
  AND token = 'CDAAe19OIEEqtrGaAyzLSI4f7a/NLPA8OLMqDsONwL8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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