SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0f502fbcf01ce3d4f52514d10fb27cdb9e974e017715ab0037443f26a336de28' 
  AND token = 'WTfEnkQNJIsVTaJfaMV7ISuxOTe8fJHwV6gR167hh14=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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