SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fd73a30a1e33afdd048ed4b99a7642bf6a7d200aa1d8f587f6237ebb3aa6c8c1' 
  AND token = 'yMByfuDeugn4pe0EKWmyxcpwJfcIPeeiqQyJuop8zns=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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