SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f25706a7aed26f244bd0a9639202ad2b6360f503f4ef849794b2fdfd906d355f' 
  AND token = '3vg6CTv83ScOXsZPRCZTc6F9sP43U31H83xcYjeoBxc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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