SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b6af9e1e87426d2ae66c271cdbc10939f968577e9dfe5cda15fdccd23a52ae74' 
  AND token = 'H2dXJC0tIflJ2CCYUpGDaK9FEMDAoT/P29wZqhbZB6w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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