SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '09e899343a0f9772953bc36828506a3344306222e0227147376441405b5a5e34' 
  AND token = 'fXcBs/6pEo0ICN5z1WGIeYRcIf1kOgz/h5/KDUhqyDM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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