SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '2a30b7f93ec71aac9cfd456317b5620839696a2b3da07ad695fbeb889994c563' 
  AND token = 'dONttEFDVBgILmLyxMdWmyXcuEyrp0WeNacbAuLhUmU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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