SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7425af81e09f6715aac6f10d144d7936c0872dd609d6b085fd9e228e9a48d5cf' 
  AND token = 'g2B1IZaqKIXnts042nTpVkhytyedeIVzEPfSVgEJklo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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