SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '089d12f15cb13cc0ac5bac4957677e7b06bec1567bb5957a4b60f8fdd9e28bc8' 
  AND token = 'xcdkWBQ/ZWZEh1Y5XceHnu+hCqWaVPS79IMj3z0ljgQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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