SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f37b2f650027c88773568e4080217eba830f8cc04bc318213fb5baa472f1faa5' 
  AND token = 'i0P3i6PbCekb38dVQtv7fJPWfFqYQxDrE17gvT0GVfM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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