SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '94916bc057c2ad62e354cbf9feb7e004f99d7e67bf620b8840652d316fe3d20c' 
  AND token = 'd8Q7kBEFC7Q7hr127C3fF4kiigFzwmOIqD7jNf2GGIg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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