SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '84dd648576e7eed083063fe1b6f8e1850718c6a6d90ce669c9e96d51263e648f' 
  AND token = 'TNFYs8JpKpv7/hhHNXTABVu+P33qZu/zcaoOarftpSg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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