SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1a79fe610fd0c9e8186587e6d73b54e568d467994d198ef3a60e154dd71f53c8' 
  AND token = 'abZM2kxqodEEtDp1MfPowf5Vkxpfd0Pcy/n9XwNw15g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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