SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a710631de90747b8ef8fa9ac50349fe0b9aff6fbad5328f1f22f56adb18c1058' 
  AND token = 'qX5nqM25fW2wLlB8tazGBz4+jlnAWHPWdU/NHg3h6Pg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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