SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3056d5630229f289bb1effde26356f0122de0d39fd403e932b7e8c0eaa29a734' 
  AND token = 'JCjWkyuiN0m1ic4YleQ6piqAT7cSTCJCWqlfafnSqys=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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