SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'fd92f0f45fb405c568a8fa6be0e7d04b3abb24855b4a2afcb6b75e08fd220550' 
  AND token = 'QzQr3/xHCbyf0F5XZFJAYqYT4rpeuwrCGdi/2UuGYxM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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