SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '860488474e7891df32bd426febf36b1be74d5eea580cea41e53e57ce1cabbc98' 
  AND token = 'nQOndHeuaQ9gV2Xgt0BmVp/UNp3YX+xcChpd1yXregA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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