SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '52da98c7e704f78784c69636268a6ed3eb1b72fc8e2bd4cbf7a55ba5453b1206' 
  AND token = 'QxQow9jzaS1tfHznc/hHMYbTjVPLgKHEYLR+6YLxPKY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

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