SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9c042be8f781bac2db038479c6387e3f37b919ea1ed5d3376af9f100c91d2b30' 
  AND token = 'Lz7142VDg7w6faIHXqJu2jqSwHeJCuWCe/iFYfVf0Fs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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