SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5365c15b2e49c6062be1f1404dad71c283fc1be352d2ba591209e83946e81274' 
  AND token = 'gRiIYSVici4stgGEj6annR0dJYN17mEyiT5/Gvv/HrQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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