SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '78180c565c6bb7debf7a379de713acea77bff244dabfed53291551f2bad22de3' 
  AND token = 'tmAC6/5Jm2uClsHRKExzmNIgfAjopFajuzOEW2mTFuM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

JSON explain

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