SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '753d9186ce5412fe2259ff50f48ec101d96d4fed3f6b65450ba2523baeac9618' 
  AND token = 'F7r4WXUAaVzxSo1NZnI7DKmobgGks2en1TbpB1yrnTs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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