SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4a9bfc72ffb218ab22e1291f69f19aa7e1addb2eceb19b490b63d20391d10185' 
  AND token = 'UWgXN06qqXZLbm0JA5eS9kSjMW81IIXgw4ks0ImFIXE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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