SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'be09ffd9816430cd86eece2b6fe2edd32a1ca5923877b9d8b6a380724c711d54' 
  AND token = 'HJPRdIvhyF/HZj2XRyya7MIs/8gCoLk2bG+GP0QwSLA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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