SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '27dff37d93556a56c137bdf6e3a6fdbb8d7387eaae9285fc8541a4d684062020' 
  AND token = 'RaQ05EQhoDdRfsXy/WHiwjw4XW9KwaZD/+9uWoSiBGY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00103

JSON explain

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