SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ef60b72afbae8aad8d86e48e9937422a896af54a43232d816baaf49a7eb0a572' 
  AND token = 'jbk2oUYkq/Dfjf/x4jKW4I7y38GiM5RnY1cyKvXIDmg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}