SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4aa06ef115975fda199b11da8569152f8c5cfd71c0bcd5c608af3d4d50f41f8e' 
  AND token = 'GI/aRT5GJrj6CdCrwXOrx9t5ttY8U8kLuvMKVf2now0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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