SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '471d1665b58fd79f4385ea43d4d71ae25dd1a82f80882bc0c6c98d94f533cee4' 
  AND token = '/RwdH/jGeYURoQTspZlENWLW4T38HPV4+fwq+WUIIzY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00071

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}