SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7c7afea02a7e61fcacd702d55f6034f552413e75129820d30fdb3b2104de548c' 
  AND token = 'TqtslXfpoQlnbz+Ogt413f3NIeHminnvdVgJiSFohOY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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