SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'a19214733f01a3225de2cb502d453211b2fd01a1e2fb32eb0b90e34039e68be6' 
  AND token = 'nCBV2D4xrNmmUZ+Vo1vermu9/75wuh0RWYYmZQ37WZA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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