SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '655fe275f00e36f92f9200617e7c9ea33741b5a204d15dd465e4b6748e662552' 
  AND token = 'O2WoMBA+hhgUxqDxqrJC8LcgOml499+WSpdDdi+57mI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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