SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9f5624d2b30733c62afbe407e922bc7c3577a612ab2474c3e22706ce8e779c26' 
  AND token = 'iiHp9Djl++kNrAEgXEap0X+0xUpdTmA0Tkkz+BCVVNw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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