SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3f79ebd8d4f742a06a24138dc52f4e1de6a819005079728fef00aed078bafb95' 
  AND token = '3utL62FWxkoQ4xHEPxNOuS7lXDddQJuKw6N2kJ2Cjy0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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