SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'bc1021e00ce56a5fd13990d8f5c07da5fb87c73cc2b9cc1faf85a86bf9ac2461' 
  AND token = 'fIPmscYZRRZNZf1z4ZCZYEK2hxmKYOzFKHmkFaFI9R0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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