SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '09f5e6f086d29acc600cfa3c3d8ee43c7c483de86650c27583dcdd722b78346a' 
  AND token = '5Xbm+YOJScP+gqxxRVeVObsbwBvi869HOI/3RWohNwY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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