Sandbox

SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '42c4dfc2ec7b06cd51eb47f9c75aab04cafb6a0b685c884d6d7a1f3914a4afb0' 
  AND token = 'um+ZgOmpcI+3TrrSgOkCN+SeVbM0trfSiZQjR9bj7KM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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