SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1d79f327cfb7c6ea7e9ae3620abe2dfb2b48eccd11955b113082257478497c9c' 
  AND token = '05CFaauYuGJkJhppvdkFJmcApS+z1GCg8hz6gQsa/RE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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