SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '97ce926727e400d0940bbfb22485aae3d4ae9a75a823460774bba5f94fe49a13' 
  AND token = 'lmVlvQnRTa37OQn8ep//LrWj69k3m6k3v/taX84mI+E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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