SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '5e2ec3405387f2c0feb41a4fcc437a302b6470a3fc7665ab36f879debf671547' 
  AND token = 'oUP1UZhtbfdkUuqnm7dK+WKF6GJGVbuxcYngzhfCsYI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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