SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9336da096ac3727819c2c6b115ed082c15f40a52b0541638f0fec92663dfe15a' 
  AND token = 'teD1FuC5NusRt6ploix3pGziWSXWC5SpjLilCIy8A28=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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