SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '57085c907bf1cb1f7d863cc82413d2c0b497ca431e41f4d9311f468a583c48da' 
  AND token = '1zGiNoLSMZN2x96kcq9yKTs6sS/oavg27JFnBtxCNG8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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