SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6a556f741055c41b57d753c325c036a0183dfa96459d9fb29c2d7e7bacb13ecf' 
  AND token = 'kjuhuU2mwFrISoICGuvjeXfxc144xfQyworJX+rsD5k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}