SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '12f59134e26294b83ce2aa46177e4743387d6481c43a811cb6ca6fb9d1ce0203' 
  AND token = 'agB+IgrHYgFhtVGVjUapnTnApCrawG9nRIvt/jj8iYA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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