SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7de5f0c50bbbc7abcd5254b6e5aebc943af1fb8ffee7b8bd6ecfd6fce159b3c7' 
  AND token = 'C8KgB1iqCGEz7oyW5nEuDn4JakT/DDfswPlqoFEEarQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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