SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '98f7e3eb0849b5cf8d652a7bb3c23220b6da9038227918bb84b77652f95b248c' 
  AND token = 'KHnt0WiDZ9GOhM2frQtosBsfreKLhaoLuHGlvq7GVuc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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