SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8d84acc3b8c0a8b1793da9ae864c91662728fd8f97c4f651e69d5f25c0fe734f' 
  AND token = 'jRpWLN93WftrajR/AokUom24BENmGF+4hZhNHJNQt7c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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