SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'ab1d9d783ceafbe35c6afcd6e9412a700fd5e21b23019552cf9a5f0fde48de4b' 
  AND token = 'Nx7lGkSIQ/bSVtxNqAlTYsIZD1oA38pp0W9bNkgpVEQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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