SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '49113b3685976f82657e4a00469bbd24f2f272991fa42276b62e0b2dca8bf96e' 
  AND token = 'mgk6p6xuC+tOPH0ZED+0MN9HoCdJfLaZIblNTO9X7Wg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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