SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'b1d5eeb02e78c1608b825a7ae0861f188c82194da677fb2ab5fafec1b723948b' 
  AND token = 'm9arXrxpV4yICRoa9R4s+02LpLs6TIpYOwiuBacjYAw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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