SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c9285374da4072f765962f30881ea24d036bd2a9e92656bb7975699250a13564' 
  AND token = '+u/hpbCCmKSukj/jA1Zk1FcoJwv0Uj7JERcUQLKvFFc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00051

JSON explain

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