SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd0612b3955094629ed5076f2e453789b3e39ae74b80ad2d6aaff08a63e6d8c23' 
  AND token = 'J0jvu7AuVYzFSt8Ch6HTZzq4tlPzaggnUGDnkaxRbNg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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