SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '554fb45c0318fa028c7dd645589fdec5542f014c35a1713bd64e075e966bf8f5' 
  AND token = 'XQbzDxT6ugBCYRFB5ZLJ/uURGjJQJ5xMMhqJgBv68AY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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