SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'afde17352b3f7a9ba0985e06919f139a7799128c647d97fe5fac6dc8a99f683c' 
  AND token = 'NijRLHaGI075nqXNLo4Ze7N2FK0feQgm3Jb9TZpmbdI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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