SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '134e708d29fc8e958c465a2111af9c771aaa93f4d0cba7cb4d40830c64d1c932' 
  AND token = 'maRj1L8WGlRJprxQh5wL+6WHvXT133NThuvlTW6CjAM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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